Accurate single-shot measurement technique for the spectral distribution of GeV electron beams from a laser wakefield accelerator

• Main Authors: C. I. Hojbota, Hyung Taek Kim, Jung Hun Shin, C. Aniculaesei, B. S. Rao, Chang Hee Nam
• Format: Article
• Language: English
• Published: AIP Publishing LLC 2019-08-01
• Series: AIP Advances
• Online Access: http://dx.doi.org/10.1063/1.5117311

We present a technique, based on a dipole magnet spectrometer containing multiple scintillation screens, to accurately characterize the spectral distribution of a GeV electron beam generated by laser wakefield acceleration (LWFA). An optimization algorithm, along with a numerical code, was developed for trajectory tracking and reconstructing the electron beam angle, divergence, and energy spectrum with a single-shot measurement. The code was validated by comparing the results with the Monte-Carlo simulation of electron beam trajectories. We applied the method to analyze data obtained from laser wakefield acceleration experiments performed using a multi-Petawatt laser to accelerate electron beams to multi-GeV energy. Our technique offers a high degree of accuracy to faithfully characterize electron beams with the nonnegligible shot-to-shot beam pointing fluctuations, particularly in the state-of-the-art multi-GeV LWFA experiments performed to push the energy frontier.